Planar sensor elements for determining the oxygen content in exhaust gas from internal combustion engines need a contacting at the surface to enable the sensor signal to be tapped off, and for provision with a heater voltage. Because the sensor element is used in exhaust systems of internal combustion engines, the contactings are subject to temperatures up to about 700.degree. C. The contactings must ensure a reliable electrical and mechanical connection in this high-temperature range, and must permit simple and reliable handling during production.
International Patent Publication No. WO 95/18965, describes an electrical contacting of a sensor element of a gas sensor, in which contacts are integrally bonded by laser welding to the connection contacts of the sensor element. In so doing, the bare, metallic contact is welded onto the connection contact.